ELJ-QF3N9DF Equivalent & Substitute Parts

Part Overview

The ELJ-QF3N9DF is a 3.9 nH unshielded multilayer ceramic inductor manufactured by Panasonic Electronic Components in the 0402 (1005 Metric) surface mount package. This component is rated for 360 mA maximum current with 150mOhm DC resistance and operates across -40°C to 85°C. The part is currently obsolete, necessitating identification of functionally equivalent alternatives for ongoing design requirements and production needs.

Substiute Parts

ELJ-QF3N9DF

Panasonic Electronic ComponentsIn Stock: 1045ELJ-QF3N9DF Datasheet

Current PartRFQ

MLG1005S3N9ST000

TDK CorporationIn Stock: 225414MLG1005S3N9ST000 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the ELJ-QF3N9DF is determined by the following critical parameters:

• Inductance Value: Must be 3.9 nH with tolerance ±0.3nH
• Package / Case: Must be 0402 (1005 Metric) for mechanical and electrical compatibility
• Mounting Type: Must be Surface Mount
• Core Material: Ceramic construction
• Shielding: Unshielded configuration

The MLG1005S3N9ST000 from TDK Corporation meets all substitution criteria. While this part exhibits higher current rating (700 mA vs. 360 mA), increased DC resistance (200mOhm vs. 150mOhm), and extended operating temperature range (-55°C ~ 125°C vs. -40°C ~ 85°C), these represent enhanced or equivalent specifications that do not preclude substitution in applications designed for the original part.

Parameter Comparison

Engineering Selection Recommendations

The MLG1005S3N9ST000 is the qualified substitute for the obsolete ELJ-QF3N9DF. Selection is based on:

• Product Status: The substitute is Active, ensuring continued availability and supply chain stability, whereas the original part is Obsolete.
• Compliance: The substitute is ROHS3 Compliant, meeting current regulatory requirements for electronic components.
• Electrical Equivalence: Both parts maintain identical inductance values (3.9 nH) and tolerance specifications (±0.3nH), with identical package and mounting configurations.
• Performance Enhancement: The substitute provides superior current handling capability (700 mA vs. 360 mA) and extended operating temperature range (-55°C ~ 125°C vs. -40°C ~ 85°C), making it suitable for applications with more demanding thermal or current requirements.

Frequently Asked Questions (FAQ)

Q: Can the MLG1005S3N9ST000 be used as a direct replacement for the ELJ-QF3N9DF?

A: Yes. Both parts share identical inductance values, tolerances, package dimensions, and mounting type. The substitute meets all mechanical and electrical compatibility requirements for direct substitution in 0402 (1005 Metric) surface mount applications.

Q: What is the impact of the higher DC resistance in the substitute part?

A: The MLG1005S3N9ST000 has a maximum DC resistance of 200mOhm compared to 150mOhm in the original part. This 50mOhm difference represents a 33% increase in resistance. Applications sensitive to resistive losses should evaluate this parameter against circuit performance requirements.

Q: Does the extended operating temperature range of the substitute affect compatibility?

A: No. The substitute's operating range of -55°C ~ 125°C encompasses the original part's range of -40°C ~ 85°C. This extended range provides additional thermal margin and does not introduce compatibility issues.

Q: Are there packaging differences between these parts?

A: No. Both parts use identical 0402 (1005 Metric) surface mount packaging with matching physical dimensions (0.039" L x 0.020" W / 1.00mm x 0.50mm) and maximum seated height (0.022" / 0.55mm).

Q: What is the significance of the Q factor difference?

A: The original part has Q = 10 @ 100MHz, while the substitute has Q = 8 @ 100MHz. This 2-point difference reflects variations in material composition and construction. Applications requiring specific Q characteristics should evaluate this parameter for their frequency of operation.

Q: Is the substitute RoHS compliant?

A: Yes. The MLG1005S3N9ST000 is ROHS3 Compliant, meeting current environmental and regulatory standards for electronic components in most jurisdictions.